This invention relates to a push-out-type writing implement, that is, pens and/or pencils of click type or push-out type; particularly to ones, in which one of writing element(s) in a main shaft is brought forward to be pushed out by slide-wise handling from outside.
In recent years, various kinds of such click-type or push-out-type writing implements are in widespread use. For example, there are commercialized a kind of writing implements in which a writing element is pushed out from and pulled into a shaft body or barrel through one-touch operation, as well as a kind of ballpoint pen that is constructed as capable of switching between three or four colors.
For most of conventional ones of push-out-type writing implements, a plurality of refills are accommodated in a hollow shaft body; and handling tips or manipulator pieces are connected to rear ends of the refills and engaged in sliding grooves as readily advanced and retracted. Only one of the refills protrudes from the forefront tip of the main shaft when one of the manipulator pieces is pushed forward and secured as locked at this position. When another one of the manipulator pieces is pushed, the already protruded one of the manipulator pieces is retracted while another refill connected to the newly pushed manipulator piece is protruded forward and become available for writing or drawing in another color. When to return and accommodate all the refills into the shaft body, either one of retracted manipulator piece is slightly pushed forward; and thereby locking of the protruded manipulator piece is lifted as to be restored to an original position by action of a restoration spring. Such restoration spring is attached to each of the manipulator pieces.
According to such construction of the conventional writing implements, one of the manipulator pieces is pushed forward and then toward central axis of the shaft body, to be locked in the sliding groove. Thus, such motion has to be allowed in a writing implement, and therefore, there arises a problem that diameter of the shaft body becomes inevitably large.
When to conduct advancing and retracting of the writing elements as well as switching operation in the writing implements, in general, manipulator pieces disposed at rear end of the shaft body is pushed and slid by pressing with a thumb. To conduct such a motion, a user has to loosen and re-grip the shaft body on beforehand of such pressing. The advancing and retracting as well as switching operation would not be achievable by a hand when the writing implement is continuously gripped by the hand.
Present invention is made in view of the above, and is aimed to reduce diameter of shaft body by avoiding a large positional shifting of the writing element. It is further aimed to simplify and reduce assembling procedures and parts, even when the writing element is pushed out by a hand constantly gripping the shaft body, and to enable improvement in ornamental appearance of the writing implements.
According to first aspect of the invention, a writing implement comprising: a plurality of manipulator pieces disposed on outside; a plurality of actuator pieces moved by respective one of the manipulator pieces, in at least foreword and rearward directions; writing elements arranged in a hollow main shaft as to be slidable along an inner face of the main shaft; springs each applying rearward stress on respective one of the actuator pieces; each of said actuator pieces comprising: a first projecting piece projecting in a traverse-sectional wise direction of the main shaft, at forefront part of the actuator piece; and a second projecting piece likewise projecting in a traverse-sectional wise direction of the main shaft, as disposed as distanced from the first projecting piece by a predetermined length; said main shaft having a small-internal-diameter part in vicinity of rearmost retracted position of the first projecting portion, and having a large-internal-diameter part larger in a diameter of the small-internal-diameter part at least in a region forefront of the small-internal-diameter part; said second projecting piece having a cam face as shaped for creating a stress in the traverse-sectional wise direction when another second projecting portion of other one of the actuator pieces axially bears down thereto; and each of said actuator pieces being connectable with respective one of the writing elements.
By such features, shape-wise construction at inner face of the shaft body and at actuating tips are simplified, as to enable cost reduction and reduction of diameter of the shaft body.
According to second aspect of the invention, a writing implement further comprising another cam face on the first projecting portion, for creating a stress in a traverse-sectional wise direction when said another second projecting portion of other one of the actuator pieces axially bears down thereto. By such features, the actuators are moved smoothly and reliably.
According to third aspect of the invention, a laterally-gathered bunch of said forefront part of the actuator pieces has a diameter substantially same with that of a laterally-gathered bunch of rear end faces of the writing elements connected with the actuator pieces.
According to fourth aspect of the invention, each of said manipulator pieces is exposed at a part to be gripped at writing or in vicinity of such to-be-gripped part and is connected with respective one of the actuator pieces as transmitted with handling force applied on the actuator piece. By such features, switching between the writing elements as well as retraction of the writing element at writing position are made by a hand continuously gripping the writing implement and without re-gripping motion.
With respect to connection between the actuator and manipulator pieces as to enable transmittance of hand-applied force, it is adoptable a connection using a connector piece or rod between the actuator and manipulator pieces. Not only such connection, it is also adoptable a connection through a refill or writing element itself onto which the manipulator and actuator pieces are respectively attached.
According to fifth aspect of the invention, each of said manipulator pieces is formed as connected with respective one of the actuator pieces and is exposed to outside from a through hole provided on the main shaft. By such features, the manipulator piece and the respective actuator piece may be integrally formed with each other, as to enhance reliability and to simplify a construction.
According to sixth aspect of the invention, at least one of said writing element is a mechanical pencil, and said actuator piece is attached on rear end portion of a fastener-bearer of the mechanical pencil. By features of the invention, a force of fastening a pencil lead in a mechanical pencil is enhanced to be substantially same with the single-use or non-multiplex mechanical pencil. To contrary, a conventional multiplex writing implement having a mechanical pencil element has a problem of low fastening force for holding the pencil lead and enduring a relatively strong writing pressure, because it is the lead casing that is held by a main structure.